Police have made a number of arrests after a protest outside a Liberal Party fundraiser in Melbourne.

Victorian cabinet ministers were jostled by protesters who attempted to block the entrance to the Victorian Infrastructure Dinner at the Regent Theatre Plaza, to show their opposition to the East West Link.

Transport minister Terry Mulder and health minister David Davis braved the crowd while others reportedly dodged the protesters by using a side entrance.

At least two people were arrested.

The two-hour protest ended when demonstrators were told Dr Napthine was already inside.

Protest organiser Anthony Main said the demonstration was a success.

"We're not surprised the premier had to sneak in the back door," he told reporters.